Absorbent articles such as diapers, training pants, incontinence products, feminine hygiene products, swim undergarments, and the like conventionally include a liquid permeable body-side liner, a liquid impermeable outer cover, and an absorbent core. The absorbent core is typically located in between the outer cover and the liner for taking in and retaining liquids (e.g., urine) exuded by the wearer.
Irritant diaper dermatitis (IDD) occurs when body waste such as feces and urine is in prolonged contact with skin. IDD is more susceptible in babies due to the sensitive nature of their skin. Frequent and prolonged skin contact with stool due to fecal incontinence and diarrhea are high risk factors for severe IDD. Many of these risks can be overcome by recent innovations in absorbent article technology, including absorbent articles having superabsorbent layers, reduced skin wetness, and superior pH control. The prevention of feces in contact with skin for a prolonged period, however, still poses a challenge. For instance, many absorbent articles include hydrophobic liquid permeable inner layers that permit urine to pass through the layer so that the urine does not contact the skin even after multiple insults. However, since feces cannot be completely absorbed into the layers of the absorbent article, prolonged contact with the skin is inevitable.
Various types of moisture or wetness indicators have been suggested for use with absorbent articles. These wetness indicators, however, fail to discriminate between body fluids such as urine and feces. For instance, known wetness indicators often cannot discriminate between feces, sweat, and urine. This could mislead a user and adds an additional burden to an already overloaded caregiver.
Many known wetness indicators are based on electrical detection using conductive elements separated by a distance on any of the layers of the absorbent article. These wetness indicators detect a change in an electrical property, such as impedance, due to the presence of an ionic liquid such as urine. The change in the electrical property triggers an alarm to indicate the presence of wetness in the absorbent article. Fecal indicators are also implemented using gas sensors such as hydrogen sulfide sensors, ammonia sensors and other biological compound sensors. But these are not capable of urine detection. Since most of these wetness indicators are highly sensitive to urine, none of them can clearly discriminate between a urine insult and a fecal insult.
Thus, a body fluid discriminating sensor that can discriminate between body exudates such as urine and feces is highly desired. A sensor that informs the caregiver that the absorbent article has been spoiled and of the particular type of insult would be particularly useful.